Alarm system



F. T. HORAN ALARM SYSTEM Jan. 30, 1945.

Filed April 15, 1942 Inventor I Frank T Horan,

His Attorney.

Patented Jan. 30, 1945 ALARM SYSTEM Frank T. Horan, Scotia, N. Y.,assignor to General Electric Company, a corporation of New YorkApplication April 15, 1942, Serial No. 439,043

7 Claims.

My invention relates to supervisory alarm systems and particularly tosystems such as are used for indicating undesirable conditionsassociated with dynamo-electric machines.

An object of my invention is to provide an improved supervisory alarmsystem for use with dynamo-electric machines and the like.

Further objects and advantages of my invention will become apparent andmy invention will be better understood from the following descriptionreferring to the accompanying drawing, and the features of novelty whichcharacterize my invention will be pointed out with particularity in theclaims annexed to and forming part of this specification.

It has been found desirable to enclose certain types of dynamo-electricmachines, and in special circumstances, to provide a special cooling orventilating medium in such enclosed machines to increase the efliciencythereof by the use of a gas such as hydrogen, or to make the machineexplosion-proof by surrounding it with an inert gas such as carbondioxide. With machines of this type, it is difficult to determine thepresence of undesirable conditions associated with the machine withoutthe use of special instruments. In order to detect such undesirableconditions and call them to the attention of an attendant, I provide analarm system arranged to give the attendant an audible signal indicatingthe presence of an undesirable condition and a visual signal indicatingthe nature of the undesirable condition.

In the drawing, I have shown an embodiment of my invention in connectionwith a dynamoelectric machine In which is adapted to be filled withhydrogen or other suitable gas for cooling.

purposes. In order to assure the operation of the electrical alarmsystem, it is adapted to be energized by a plurality of sources ofelectrical power supply, including an alternating current source ofpower supply H and a direct current source of power supply l2. Theset-wo'sources of power supply are adapted to be'connected anddisconnected to their respective alarm circuits by circuit breakers l3and M, respectively. Visual signals including pilot lights I5 and I6 areconnected to the sources of power supply I I and I2, respectively, toindicate the ener-gization or deenergization of the respective sourcesof power supply. A plurality of audible signal devices, such as horns I!and I8, is connected in circuit with the sources of electric powersupply H and I2, respectively, cuit breaker is is connected in serieswith the energizing circuits of these audible signal devices forstopping the operation thereof when desired. Circuit breaker 20 and 2|also are connected in circuit with the audible signal devices I! and I8,respectively, and are adapted to be operated by I a common solenoidcontrolled relay armature 22.

A solenoid coil 23 is arranged to be normally energized to maintain thecircuit breakers 20 and 2| open, thereby maintaining the circuits of theaudiblesignal devices I1 and I8 deenergized when the sources of electricpower supply I l and I2 are energized. This solenoid is arranged inseries with a plurality of sets of circuit breaker contacts 24 and 25 ofcircuit breakers operable in response to predetermined conditionsassociated with the dynamo-electric machine l0. Under normal operatingconditions with the sources of electric power supply I l and I2energized, solenoid operating coils 26 and 21 are adapted to beenergized by the direct current source of electric power supply l2through current limiting resistors 28 and 29, respectively, therebyclosing the circuits of the contacts 24 and 25 by circuit breakercontactors 30 and 3!, respectively. An-

and a manually operated cirother circuit breaker having contacts 32connected in series with the circuit breaker contacts 24 and 25 and thecircuit breaker operating coil 23 is arranged to be closed by operationof a solenoid coil 33 energized from the alternating source of electricpower supply ll". When both of the sources of electric power supply IIand I2 are energized and the circuit breakers l3 and I4 are closed, thecircuit of the circuit breaker solenoid coil 23 is energized from thedirectcurrent source of electric power supply through the circuitbreaker contacts 24 and the contactor 30, the circuit breaker contacts25 and contactor 3|, and through the circuit breaker contacts 32 andcontactor 34. It is desirable that an audible signal should be given toindicate the failure of power on either of the sources of electric powersupply. If the alternating current source of electric power supply I Ishould fail, the circuit breaker solenoid coil 33 would becomedeenergized and the circuit breaker contactor 34 would open the circuitbetween the breaker contacts 32. This would result in the deenergizationof the circuit breaker operating coil 23, with the result that thecircuit breaker 2| would be closed and the audible signal device I 8would be energized by the direct current source of electric power supplyl2, thereby providing an audible signal indicating an undesirablecondition some place in the system. The visual signal pilot light 15would be deenerglzed, and thereby would indicate that the undesirablecondition was the deenergization of the alternating current source ofelectric power supply. Should the alternating current source of powersupply remain energized and the direct current source of electric powersupply 12 become deenergized, the circuit breaker operating coil 23would be deenergized and the circuit breaker 20 would be closed, therebyenergizing the audible signal device I! by the alternating current.source of power supply H and {providin an audibl signal indicating thatan undesirable condition existed in the system. Under these conditions,an examination of the visual signal devices will indicate that thevisual signal pilot light I 8 is extinguished, thereby indicating thatthe direct current source of electric power sup-- ply is deenergized.

The dynamo-electric machine 10 may be provided with a large numberofinstruments incorporating circuit breakers or switches for closingalarm circuits to indicate the presence of undesirable conditionsassociated with the dynamoelectric machine. These undesirable conditionsmight be due to a variety of circumstances, such as excessivetemperatures of the windings of the machine, excessive temperatures inthe bearings of the machine, the lack of an adequate supply oflubricating oil to the bearings of the machine, the presence of foreigngases in the ventilating medium in the machine, the presence of waterwithin the machine housing, undesirably high or low pressure of theventilating medium in the machine, and a number of other similarconditions. My improved alarm system is illustrated in the drawing inconnection with two of these conditions, asit is obvious that alarmcircuit breakers and circuits could be arranged to operate in the samemanner by merely locating circuit breakers and the proper instrumentsfor operating such circuit breakers responsive to the presence of any ofthe above undesirable conditions. An alarm circuit breaker 35 isarranged to be operated by a float 36 responsive to liquid level in thehousing of the dynamo-electric machine ID to indicate an accumulation ofwater or oil from within the housing. The circuit breaker 35 is arrangedto be closed if the accumulation of water or oil exceeds a predeterminedamount and is connected in a circuit across the circuit breaker operating coil 26, so as to provide a shunt across this operating coil inresponse to a predetermined undesirable amount of accumulated liquidfrom within the machine housing. This causes a deenergization of thecircuit breaker operating coil 26, thereby opening the circuit betweenthe circuit breaker contacts 24 and deenergizing the operating coil 23of the audible signal device circuit breaker. This causes the audiblesignal circuit breakers and 2| to close and provide an energizingcircuit for the audible signal devices I 1 and 18 which produce anaudible signal indicating the presence of an undesirable condition inthe system. The deenergization of the circuit breaker operating coil 26also provides for the closing of a circuit through a visual signaldevice including a pilot light 31 through circuit breaker contacts 38and contactor 35. The visual signal given by the pilot light 31'inicates the particular undesirable condition existing in the system,and the operator may then shut off the audible signal produced by thehorns l1 and I8 by the operation of a manually operable circuit breaker4D to close circuit breaker contacts 4|, so as again to energize thecircuit breaker operating coil 22 and open the circuit breakers 24 and 2I thereby deenergizing the audible signal devices I! and I8. In thislatter position of the circuit breaker 40, a circuit is closed throughcircuit breaker contacts 42 which energize a visual signal deviceincluding a pilot light 43 which indicates that one of the manuallyoperable circuit breakers connected with one of the alarm signals hasbeen manually operated to the "oil" position for the audible signaldevices. With such an arrangement, the audible signal devices arecapable of being operated in response to any undesirable condition whichmight occur in the machine and which is provided with an alarmindicating circuit breaker system, and the operation of the audiblesignal in response to the presence of one undesirable condition is notaffected by and is independent of the presence of another undesirablecondition if the manually operable circuit breaker in the alarm systemis placed in the horn-off position after the operation of one of thealarms has been determined. Furthermore', the presence of the particularundesirable condition remains indicated by the pilot light in the alarmsystem as long as the undesirable condition continues to exist. In thealarm system described above, the visual signal indicating pilot light31 will be extinguished after the water in the machine housing has beenremoved, as the circuit breaker 35 then will be opened and the circuitbreaker operating coil 26 again will be energized, so as to open thecircuit between the circuit breaker contacts 38. When the undesirablecondition has been corrected, the manually operable circuit breaker 40must be returned to the position shown in the drawing with the circuitbreaker contacts 4| and 42 in open circuit relationship in order toplace the audible signal devices H and I8 again in circuit with thecircuit breaker contacts 24 responsive to the operation of the circuitbreaker operating coil 26.

In the drawing, I have shown a second alarm circuit breaker operable inresponse to the gas pressure within the dynamo-electric machine l0 andprovided with a contactor 44 arranged to complete a circuit with circuitbreaker contacts 45 or 46 if the ventilating gas pressure within themachine is lower or higher, respectively, than predetermined safeoperating values. If the circuit breaker contactor 44 is operated toclose a circuit with the circuit breaker contacts 45 or 46, the circuitbreaker operating coil 21 is shunted, and thereby deenergized, resultingin the opening of the circuit between the circuit breaker contacts 25.This deenergizes the audible signal circuit breaker operating coil 23and closes the circuit breakers 20 and 2|, thereby providing an audiblesignal by horns I! and l8, indicating the presence of an undesirablecondition in the system. This deenergization of the circuit breakeroperating coil 21 also closes an electric circuit through circuitbreaker contacts 41 by a circuit breaker contactor 48 and energizes avisual signal device including a pilot light 49 which indicates thenature of the particular undesirable condition to be the presence of anundesirable pressure within the dynamoelectric machine 10. As in theother alarm system. the operator may turn of! the audible signal byoperation of a circuit breaker 54 to its horn-off position, therebyclosing a circuit through circuit breaker contacts 5i again to energizethe audible signal circuit breaker opcrating coil 23 and open thecircuit breakers 20 and 2| to prevent further operation of the horns l1and I8. In this latter position of the manually operable circuit breaker50, circuit breaker contacts 52 are closed and thereby energize thevisual signal device pilot light 43, which indicates that one of themanually operable alarm circuit breakers is in the horn-off position.This provides for the operation of the audible signal de-' vice inresponse to the presence of other undesirable conditions associated withthe dynamoelectric machine l irrespective of the-condition of theventilating medium pressure in the machine.

It has been found desirable to indicate the deenergization of the directcurrent source of electric power supply by a signal other than thesingle visualsignal pilot light l6, and this condition is indicated bythe deenergization of the horn circuit breaker operating coil 23 whichcompletes the energizing circuit of the alternating current audiblesignal device l1 through the circuit breaker and provides an audiblesignal. The horn l1 may be turned off by opening the circuit breaker l9until the direct current source of electric power supply I2 isreenergized. The reenergization of the direct current source of electricpower supply is indicated by the visual signal light It and results inthe reenergization of the alarm circuit breaker operating coils 26 and21 and the audible signal circuit breaker operating coil 23, therebyplacing the system again in condition for giving indications by all thesignal devices. Thus, I have provided an alarm system which willindicate by an audible signal the presence of any undesirable conditionassociated with a dynamo-electric machine to whichthe system is appliedirrespective of the presence of any other undesirable conditionassociated with the system, and a visual signal to indicate theparticular nature of the undesirable condition for which the alarmsignal is iven.

A test switch 53 is provided connected in series with the direct currentsource of power supply and the signal circuit breaker operating coils 26and 21 for testing the operation of the alarm signal devices and circuitbreakers. Opening the switch 53 deenergizes the circuit breakeroperating coils 23, 26, and 21, and the various audible and visualsignal devices l1, i8, 31, and

49 are energized. By closing the test switch 53. all of the circuitbreaker coils 23, 26, and 21 are reenergized and the signal devices l1,I8, 31, and 49 are deenergized.

While I have illustrated and described a particular embodiment of myinvention, modifications thereof will occur to those skilled in the art.I desire it to be understood, therefore, that my invention is not to belimited to the particular arrangement disclosed. and I intend in the apended claims to cover all modifications which do not depart from thespirit and scope of my, invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1. In a supervisory alarm system, a device to be supervised, circuitclosing means operable by said device, a first source of electric powersupply, a second source of electric power supply, a relay having awinding connected in circuit with said first source of electric powersupply and having circuit closing contacts, a second rei lay having awinding connected in circuit with said second source of electric powersupply and be supervised, a circuit closing means operable to closedcircuit position in response to a predetermined condition of saiddevice, a first source of electric power supply, a' second source ofelec tric power supply, a first circuit breaker means having a windingconnected in circuit with said first source of electric power supply, asecond circuit breaker means having a winding connected in circuit withsaid second source of electric power supply, shunting means for saidwinding of said second circuit breaker means including said circuitclosing means, a third circuit breaker means having a winding connectedin series in a normally closed circuit through said first and secondcircuit breaker means, and two audible signal devices each connected toa different one of said two sources of electric power supply throughsaid third circuit breaker means.

3. In a supervisory alarm system, a device to be supervised, a firstsource of electric power supply, a second source of electric powersupply, a first circuit breaker means having a control winding connectedin circuit with said first source of electric power supply, a secondcircuit breaker means having a control winding connected in circuit withsaid second source of electric power supply, a plurality of circuitclosing means operable to closed circuit position in response topredetermined conditions of said device for shunting and deenergizingsaid winding of said .second circuit breaker means, a third circuitbreaker means having normally open circuit 4. In a supervisory alarmsystem, a device to be supervised, a first source of electric powersupply, a secondsource of electric power supply, a first circuit breakermeans having a control winding connected in circuit with said firstsource of electric power supply, a second circuit breaker means havinga. control winding connected in circuit with said second source orelectric power supply, a plurality of circuit closing means operable toclosed circuit position in response to predetermined conditions of saiddevice for shunting and deenergizing said control winding of said secondcircuit breaker means, a third circuit breaker means having normallyopen circuit breaker contacts and a winding connected in series in anormally closed circuit through said first and second circuit breakermeans, two audible signal device's each connected to a different one ofsaid two sources of electric power supply through said third circuitbreaker contacts, a visual signal device, and means for connecting saidvisual signal device to one of said sources of electric power supplythrough said second 'circult breaker means on deenergization of saidsecond circuit breaker control winding.

5. In a supervisory alarm system, a device .to be supervised, a firstsource of electric power supply, a second source of electric powersupply,

i a first circuit breaker mean having a control winding connected incircuit with said first source of electric power supply, a secondcircuit breaker means having a control winding connected in circuit withsaid second source of electric power supply, a circuit closing meansoperable to closed circuit position in response to a predeterminedcondition of said device for shunting and deer:- ergizing a winding ofsaid second circuit breaker means, two audible signal devices, meansincluding a third circuit breaker having a control winding connected inseries with said first circuit breaker means and said second circuitbreaker means in a normally closed circuit for connecting each of saidaudible signal devices .to a different one of said two sources ofelectric power supply for operation of one of said audible signaldevices by one of said sources of electric power supply ondeenergization of the other of said sources of electric power supply andfor operation in response to said predetermined condition of saiddevice, a visual signal device, means for connecting said visual signaldevice to one of said sources of electric power supply through saidsecond circuit breaker means on deenergization of said control windingof said second circuit breaker means, and means in circuit across saidsecond circuit breaker means for deenergizing said au-.

dlble signal devices independently of the condition of said circuitclosing means and independently of said visual signal device.

6. In a supervisory alarm system, a device to be supervised, a firstsource of electric power supply, a second source of electric powersupply, a first circuit breaker means having a control winding connectedin circuit with said first source or electric power supply, a secondcircuit breaker means having a control winding connected in circuit withsaid second source of electric power supply, a circuit closing meansoperable to closed circuit position in response to a predeterminedcondition of said device' for shunting and deenergizing a winding ofsaid second circuit breaker means, a third circuit breaker means havingnormally open circuit breaker contacts and a winding connected in seriesin a normally closed circuit through said first and second circuitbreaker means, two audible signal devices each connected to a differentone of said two sources of electric power supply through said thirdcircuit breaker contacts for operation or one or said audible s18- naldevices by one of said sources of electric power supply ondeenergizatlon of the other of said sources of electric power supply andfor operation in response to said predetermined condition of saiddevice, a visual signal device, means for connecting said visual signaldevice to one or said sources of electric power supply through saidsecond circuit breaker means on deenergization of said control windingof said second circuit breaker means, and means in circuit across saidsecond circuit breaker means for closing the circuit of said thirdcircuit breaker means winding across said second circuit breaker meansindependently of the condition of said circuit closing means andindependently of said visual signal device.

7. In a supervisory alarm system, a device to be supervised, a firstsource of electric power-sup- P y. a second source of lectric powersupply, a first circuit breaker means having a control winding connectedin circuit with said first source of electric power supply, a pluralityof second circuit breaker means each having a control winding connectedin circuit with said second source of electric power supply, a pluralityof circuit closing means'each operable to closed circuit position inresponse to a difierent predetermined condition of said device forshunting and deer:- ergizing a winding of a diiferent one of said secondcircuit breaker means, a third circuit breaker means having normallyopen circuit breaker contacts and a winding connected in series in anormally closed circuit through said first and second circuit breakermeans, two audible signal devices each connected to a different one ofsaid two sources of electric power supply through said third circuitbreaker contacts for operation of one of said audible signal devices byone of said sources of electric power supply on deenergization of theother of said sources of electric power supply and for operation inresponse to said predetermined conditions of said device, a plurality ofvisual signal devices, means for connecting each of said visual signaldevices to one of said sources of electric power supply through one ofsaid second circuit breaker means on deenergization of said controlwinding of said latter second circuit breaker means, and means incircuit across each of said second circuit breaker means for closing thecircuit or said third circuit breaker means winding across said lattersecond circuit breaker means independently of the condition of other ofsaid circuit closing means.

FRANK T. HORAN.

